(function() { 'use strict'; // Check to make sure service workers are supported in the current browser, // and that the current page is accessed from a secure origin. Using a // service worker from an insecure origin will trigger JS console errors. const isLocalhost = Boolean(window.location.hostname === 'localhost' || // [::1] is the IPv6 localhost address. window.location.hostname === '[::1]' || // 127.0.0.1/8 is considered localhost for IPv4. window.location.hostname.match( /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/ ) ); window.addEventListener('load', function() { if ('serviceWorker' in navigator && (window.location.protocol === 'https:' || isLocalhost)) { navigator.serviceWorker.register('service-worker.js') .then(function(registration) { // updatefound is fired if service-worker.js changes. registration.onupdatefound = function() { // updatefound is also fired the very first time the SW is installed, // and there's no need to prompt for a reload at that point. // So check here to see if the page is already controlled, // i.e. whether there's an existing service worker. if (navigator.serviceWorker.controller) { // The updatefound event implies that registration.installing is set const installingWorker = registration.installing; installingWorker.onstatechange = function() { switch (installingWorker.state) { case 'installed': // At this point, the old content will have been purged and the // fresh content will have been added to the cache. // It's the perfect time to display a "New content is // available; please refresh." message in the page's interface. break; case 'redundant': throw new Error('The installing ' + 'service worker became redundant.'); default: // Ignore } }; } }; }).catch(function(e) { console.error('Error during service worker registration:', e); }); } }); })();